If you haven't used speech recognition on your computer before, then Windows will take you through a guide which will help you get started and make This is actually all you need - the text in the screenshot above was dictated through my headset and then inserted into the TextBox control as text,Īs soon as you initialize a SpeechRecognizer object, Windows starts up its speech recognition application, which will do all the hard workĪnd then send the result to the active application, in this case ours. SpeechRecognizer speechRecognizer = new SpeechRecognizer() Public partial class SpeechRecognitionTextSample : Window Namespace WpfTutorialSamples.Audio_and_Video With that taken care of, let's start out with an extremely simple speech recognition example: Depending on which version of Visual Studio you use, the This assembly is not a part of your solutions by default, but we can easily add it. To do that, we'll be using the SpeechRecognition class, which resides in the System.SpeechĪssembly. Way around, by turning spoken words into text. In the previous article we discussed how we could transform text into spoken words, using the SpeechSynthesizer class. Here is the trace from starting the first time, from the first session event through the delivery of the first video frame to the GUI:ġ65 12244,3484 21:40:50.25101 CTopologyHelpers::Trace 172 12244,3AB8 21:40:50.Audio & Video: Speech recognition (making WPF listen) Perhaps I need to iterate the aggregate source, extract the individual media sources What steps are necessary for me to unload the topology in order to build a new one? Clearing the session on the topology and releasing all of my smart pointers is not enough.What is necessary for me to restart an IMFMediaSession containing live sources?.When re-creating the session I was unable to create a new aggregate source, indicating I did not properly release it.Īlso, I note that I have not taken any steps to mark the Source Nodes as live sources, I assume that would happen automatically? I have tried pausing the session, stopping the session, and also attempted to unload the session and re-create it. A picture of the topology is included at the end, along with some MFTrace output. Video source appears to never restart delivering frames. When the session stops, I see the Sample Grabber Clock stop, and end of Stream notifications, but when the session restarts, I receive the session start message, and see basically the same events, including an OnClockStart event for both media sinks, but the Only), but I am unable to restart the session. Everything works the first time I run the session (preview I am attempting to use the Media Session, with an aggregate source containing a webcam+microphone sources. I am attempting to build a live preview/recording application using Media Foundation. TL DR: See the section "So My Questions Are:" - This is very long, thanks for looking. _timeStamp : does not reflect the seeked position. M_pSourceReader->ReadSample((DWORD)MF_SOURCE_READER_FIRST_AUDIO_STREAM, 0, NULL, &dwFlags, &_timeStamp, &pSample) Whenever I change the slider position it calls Seek(()) (in pseudo code) Hr = PropVariantToInt64(var, &hnsDuration) HRESULT hr = m_pSourceReader->GetPresentationAttribute(MF_SOURCE_READER_MEDIASOURCE, MF_PD_DURATION, &var) Windows::Foundation::TimeSpan GetDuration() The position is tied to a slider between 0 and the audio max time obtained from: Hr = m_pSourceReader->SetCurrentPosition(GUID_NULL, var) Hr = InitPropVariantFromInt64(position.Duration, &var) Void Seek(Windows::Foundation::TimeSpan position) I have this function which sets the position: I want to be able to seek anywhere in the audio timeline. I'm using IMFSourceReader to grab samples on an audio file. Could I just make a pointer to that function from the invoke method in IMFAsyncCallback? and how does it know to go to that callback function? I don't see how the pointer and event handle direct there each time Really all I need is to implement his function OnRenderCallback ( IMFAsyncResult * result )but that's where I sort of hit a wall. Also the above linked example doesn't quite work since it requires /clr or /ZW in the command line for his implementation AsyncCallback.hĪnd I am using openFrameworks which conflicts with both. Problem is I just don't know enough about the asynchronous callbacks and the documentation for them just isn't clear to me. Thankfully someone sort of did most of the work for an example they were building for BUILD2014 and posted the code on github. I am developing and I need an callback method to refill the buffer. Basically I made some simple oscillators for a synthesizer So I've looked through the samples for the Media Foundation audio and they basically have all the functionality I need except for they don't really implement a callback for when the audio buffer is empty.
0 Comments
Leave a Reply. |